Re: [BProc] Clustermatic: smooth install, just little trap(s)

[Erik A. H. <er...@he...>]

On Sun, Mar 24, 2002 at 01:08:18PM +0100, ha...@no... wrote:
> I installed Clustermatic according to included README (on top of fresh
> RH7.2). Most things worked great, I have just these little notes:

Cool.

> 1) After "rpm -Uvh *" previous kernel modules are gone. This is a
> problem if you still need them to make system bootable with new
> kernel. I used floppy boot (did not want to touch some things on hd
> during these experiments) and was unable to create new boot floppy
> without old fat.o msdos.o vfat.o and loop.o.
> 
> If you want to avoid this trap, copy /lib/modules somewhere before
> kernel upgrade.
> 
> (Just "cat kernel>/dev/fd0; rdev ..." will not help if your root
> partition is RH72 default ext3.)

Yeah, I've noticed that myself.  That's an artifact of the way the Red
Hat RPMs work, I'm afraid.  I imagine you should be able to install
"kernel" and "kernel-smp" with -i instead of -U.  They shouldn't
conflict with the existing kernel packages.

The ext2 filesystem code should, however, be able to mount an ext3
file system.  You just won't get the journalling features.

> 2) I was rather disappointed that my old Scyld phase1 images on nodes
> did not work with Clustermatic. It is likely that I should blame the
> old system and not the new one, but anyway - I somehow believed that
> once the node ever beoboots, I never ever have to touch phase1 images
> again (unless I change the hardware). If it RARPs and starts once, it
> should RARP and start with future master node setups as well.
> 
> I was wrong. My old Scyld beoboot 1.1.16 with 3c905B and driver
> v0.99Rb 8/8/2000 just RARPs forever with Clustermatic master (while it
> works with old Scyld master).
> 
> OK, I will just upgrade phase1 images on all local harddisks...  :-(
> 
> My question is: How long should I expect my phase1 images to stay? How
> long will be my "forever" this time?

Well, I'm not going to say "forever" but I would expect them to be ok
for at least the next few revs.  Basically the following changed since
scyld:

* Two Kernel Monte boot image changed a bit to accomodate Alpha boot
  images.

* The RARP step was extended to include an architecture tag and in the
  case phase2 BProc version stuff.

* Boot images are downloaded with the same multicast protocol as the
  libraries.

The next thing that I can see which would require a change in phase 1
boot images would be an improved multicast protocol for library and
boot image distribution.  The current protocol is just something I
made up.  It seems to mostly work but I know it sucks.  I don't have
any replacement in mind right now.  I just know the current
implementation kinda sucks.

I do understand your annoyance with changing the phase 1 images.  On
our cluster the phase 1 image is stored in flash along with LinuxBIOS.
Having to come up with a working image and doing the re-flashing step
on those machines always makes me really nervous.

I try to avoid changing the phase 1 boot as much as possible.

- Erik